Posted
by
Soulskill
on Friday January 14, 2011 @07:29PM
from the denny-crane dept.

sgunhouse writes "Wired has a story up on the lethality of airborne prions. It should be noted that prions (which cause 'mad cow disease' and similar disorders) are not normally airborne, and take a long time to kill the infected animal, but so far are 100% lethal if something else doesn't kill the animal first. So, they are not likely to be useful as a biological weapon (my first thought when reading their headline), but they present another safety precaution to consider."

I am not a biologist, but based on my reading of TFA, the scientists successfully infected immunodeficient and immunocompetent mice. It's counterintuitive, but the fact that the disease incubated in the immunodeficient mice at the same rate as the immunocompetent mice is what makes the research significant.

The immune system actually seems to play some kind of a role in prion diseases, acting as a kind of Trojan horse mechanism to spread the infection. It's not totally clear how this works, but the research supports that it happens. So what these scientists did is they inoculated immunodeficient mice with prions and observed them coming down with the prion disease in pretty much the exact same way as the immunocompetent ones. This establishes that a functioning immune system is not actually necessary for infection via aerosol. This means that an immunodeficient mouse, even when kept in semi-isolation, can potentially come down with a prion disease from an aerosol source even when it doesn't come in direct contact with any infected tissues.

That's a pretty big deal when you consider a lot of scientists in research laboratories might be working with immunodeficient mice, in the mistaken assumption that the mice will be safe from prion infection. The recommendation of this paper is that research lab safety guidelines note aerosols as a possible vector for prion infections, which they do not do now. I don't think this is really a warning aimed at keeping people from being infected. For the time being, at least, it's more about keeping research from being spoiled when lab animals come down with infections from unforeseen aerosol sources.

Here we tested the cellular and molecular characteristics of prion propagation after aerosol exposure and after intranasal instillation. We found both inoculation routes to be largely independent of the immune system

Admittedly quoted out of context. But it does mean that no, having an immune system that works properly is not in and of itself enough to protect you from aerosol prions.

And despite what TFS says, I can see uses for this in biological warfare. A person exposed to airborne prions cannot transmit the disease to another human being, as person-to-person transmission has only been observed to occur via ingestion of tissue. So, unlike a viral or bacterial agent, there's no risk of a bioweapon a

The other major problem with bioweapons is that they cannot be aimed only at an enemy. They will affect everyone: Friend or foe, combatant or non-combatant, adult or child. Plus, unlike other non-discriminant killers, like land mines, you can never clear an area. You could nuke the area, but the biological agents could return, carried by insects or water or birds.

I did cover that with the second paragraph of my post. Prion bioweapons wouldn't be person-to-person contagious the way that viral or bacterial bioweapons are. Hence the comparison between prion weapons and chemical weapons, where in both cases only the people initially exposed will be affected. I should also clarify that I find the notion of actually using bioweapons to be a crime against humanity, but I have no problem hypothesizing about their use.

Also, the comparison to land mines is inept. Land mines last a long time, but only kill or maim one person per mine. Bioweapons don't last a long time, but can kill or main many people per deployment.

you can never clear an area. You could nuke the area, but the biological agents could return, carried by insects or water or birds.

No, this is demonstrably wrong.

Some, not all, pathogens are transmissible through animal vectors. If you were to weaponize bubonic plague then there could still be rodent carriers inside the exposed area after all human beings have been evacuated or died. Not every bioweapon has an animal vector available to it however, and even the ones that do, the animal must be at least partially asymptomatic in order to remain a threat, or it's going to die in short order. The "worst case" would be a disease that can jump species to something ubiquitous, like rats or mosquitoes, and can infect those species without killing them.

If you'd stated that some bioweapons remain a threat in a region after deployment, I would have accepted your argument as valid, but the way your post is written suggests that you think all bioweapons can, which is wrong.

Also, you listed "insects water and birds". Insects and birds belong on that list, and you didn't mention any other animals like rats, but water is another matter entirely. Waterborne transmission due to contamination is temporary. Water itself cannot act as a host. When a disease is waterborne, it either spends part of it's life-cycle in water, like the Guinea Worm, or it's the result of contamination via feces or dead organisms, like cholera.

I meant as physical carriers, not as biological vectors. If you've got an airborne weapon, it will be picked up by flying creatures and rainfall, much like pollen. It can be physically transported out of the target area, and back in again.

More importantly, take more precautions if you work with slaughtered pigs and cows in a meat packing facility/slaughterhouse.

Indeed, just below TFA was this [wired.com] little blurb pointing out exactly that - workers on a pig brain processing line came down with a serious autoimmune disorder linked to heavy exposure to pig brain pieces. Not prion linked apparently, but certainly a potential occupational hazard to all you Zombies out there.

The only pause I went through was a triple check of the title, before I realized it said nothing about lethal airborne prisons. I thought it made sense, with Nicholas Cage being the exception to the rule.

Actually, the primary way of disposing of diseased animals at meat rendering plants is by putting them through a device very similar to a wood chipper. See the episode of Dirty Jobs where they visit such a facility for a very disturbing demonstration of such a device.

However, I've previously read that cows infected with Mad Cow Disease are disposed of by dissolving them in lye, not burning, precisely due to the risk that prions could survive the fire and become airborne.

However, I've previously read that cows infected with Mad Cow Disease are disposed of by dissolving them in lye, not burning, precisely due to the risk that prions could survive the fire and become airborne.

A recent study showed that 100% of mass murderers ingested some form of dihydrogen monoxide within 48 hours of killing their victims. Warn your children about the dangerous effects of dihydrogen monoxide today!

Yeah, I heard some guy talking about this big tournament, saying "there can only be one". I assume he meant winner, but, whatever, I wasn't really paying attention. His hair was too long for me to take him seriously.

I agree that it does look like birth is pretty lethal, but there are billions of us still alive, so saying that birth is 100% lethal isn't accurate. It's likely it is accurate for every one of us alive here today, but we can't be sure they won't come up with an immortality spell tomorrow, so birth has been shown to be lethal in a much lesser percentage than 100 of observed cases so far.

There's an account of him being taken up in Genesis, so the book of Enoch shouldn't even need to be considered. Plus, responding to AC, birth was lethal for Jesus as well. He just came back afterwards.

You're making a semantic argument or what? Because I'd argue that there is a big difference between "Uninfected lifespan: indefinite" to "Infected lifespan: finite." At least, to the infected person. To argue "Everyone is going to die, so if it's not immediate it doesn't matter" is idiotic.

I can't find a source right now, but I remember hearing that "old age" has not been an acceptable cause of death since the 80's. Nowadays the death certificate has to have something specific on it. (Usually cancer.)

A weapon that destroys your enemy's economy in a matter of years is still a viable weapon. Especially if it's hard to detect (ie by the time everyone shows signs of being sick, you are no longer deploying the weapon). This is scary stuff.

In fact, this strikes me as a damn near *perfect* biological weapon (if you can find or make enough malformed prions, and the findings apply to large mammals, like people).

100% lethal, non-communicable (so you don't have to worry about travelers spreading it back to "your people"), virtually impossible to detect and a long enough incubation period to make it impossible to quarantine or trace back to the source. Like you said, so what if people don't start dropping dead for a couple of years? That's a *

Provided you don't make soylent green out of the bodies and dispose of them adequately, I don't see how it could be a problem. Otherwise we'd have many more cases of C-J disease in populations near cemeteries...

Apart from a few whackjobs, the whole point of WMDs is using them to threaten people to accomplish other goals - not actually using them.

True... unless, of course, you come up with a viable treatment for your weapon and can prove it works. Then you could place an entire population under a death sentence... with you holding the reprieve.

That would probably buy you a lot of influence to accomplish those other goals.

It's not completely unprecedented though. The biosciences weapon theorists have been worrying about control of airborne transmission, by tailored pathogens that target a particular ethnic group selectively, for at least a decade now. Some basic conclusions have become almost tautological, particularly two of them, that some nations with particularly homogeneous populations would benefit from such selectivity much more than other, more diverse, nations, and that some racist groups would make producing such w

Prions are strange in the sense, they are almost on the dividing line between living and non living. They have no DNA/RNA, no need to breath or even to eat, but they replicate that makes them different from venom and poison. How long do the exist in prion form left to themselves I wonder. Can they exist in some dried powder form forever? Or do they spontaneously disintegrate into constituent compounds?

Leather tanning industry has some really weird mix of chemicals and some of them involve brain matter. Hope the left over prions on the leather jackets degrade or wear off.

is silver iodide used in rainmaking living? it catalyzes a chain reaction

is a bit of ice in supercooled water living? it catalyzes a chain reaction

take a prion, put it at the right spot in a susceptible brain, and it makes a cascade of prions. this is chemistry, not life. if you call a prion living, lots of chain reactions in nature you would have to call living

circletimessquare correctly addressed the "living" issue. Prions are plain dead proteins, they're not alive in any sense. But there is another, even simpler misconception.

but they replicate

No, they don't. Prions have no ability whatsoever to replicate. They are plain boring proteins like all other proteins and as such are completely dependent on the common protein biochemistry (coded in DNA - transcribed to RNA - translated to the actual protein sequence - folded to yield a particular, specific 3D structure

Wow. Those genetically modified mice "tga20 transgenic mice overexpressing PrPC" bred to be hyper-susceptible seem to be highly susceptible. After 15+ years of this "ice 9" business I'm still waiting for results that in any way meet Koch's Postulates. Oh yeah, let's stop calling this protein "prion" and start calling it a proteinaceous "toxin" which is what it is. Moreover, since this Nobel Prize winning hypothesis in no way seems to conform with the reality of widely spreading communicable encephalitis i

Making claims that biochemists working on prions "don't like to get dirty" is both insulting and disingenuous. Animal models are, in fact, used here to demonstrate that purified PrPsc (misfolded prion protein) is infectious in live hosts, in addition to triggering misfolding in vitro. No one uses farm animals because they're large, expensive, and there's no compelling reason to incur that cost when simpler model animals (here, hamsters) will do.

why not entertain the notion that this is a slow virus and that the symptomatic misfolded protein is a mere phenotype, possibly detrimental, but not causal

Well, because the linked paper was able to amplify the infective population of PrPsc in a cell-free system, which would not be conducive to the amplification of a virus.

I understand the appeal of an underdog hypothesis, but unless you can present a better argument that isn't comprised of ad hominems, vague conspiracy theories, and a smattering of scientific claims answered by 5-year-old literature, I'm not convinced.

After 15+ years of this "ice 9" business I'm still waiting for results that in any way meet Koch's Postulates.

But Laura Manuelidis is claiming that vCJD and others are caused by "a slow-acting virus"... and Koch's Postulates aren't strictly applicable to viruses either. The best that Manuelidis has managed to do is to isolate "virus-like DNA signatures" -- which does not even prove the presence of a virus, let alone that a virus is causative. So in the best case scenario, Manuelidis may have raised some questions, but has been no more successful at meeting your preconditions for accuracy than anybody else. You apparently just think she's "fighting the good fight" because -- much like Jenny McCarthy -- she questions the prevailing theory. That attitude is bad science.

Yeah, but it won't necessarily rot your mind in the process like prion disease does. Could be a horrific terrorist weapon, assuming the terrorists are long-sighted enough - poison a large number of the population with something that they won't even know they have for 5-20 years, then watch society crumble as half the population suffers from mindrot.

They don't even need to do the research now to see if it works or not.

People who then know more than those that don't bother checking. Tribes with this characteristic are thought to optimize their use of limit resources slightly over people who would never think to check for themselves.

Anything I can think of is 100% lethal if something else doesn't kill the animal first.

Yep... even water. Come to think of it... 100% of animals that were alive and then died ingested some water during their lifetime. This makes water some pretty dangerous stuff.

I suppose the computer equivalent to throwing prions into the air is pointing a fan at a fully powered up computer with open case running full blast, and dumping a 5 pound bag of copper and iron filings across the path of the fan, so

I mean it seriously.
If the prions do not reproduce in culture, they could pass any quarantine test applied to a sample returned from Mars or from another planet and they could still infect the scientists that breath them in. With an incubation period of 10 years, perhaps a lot of people could become infected by such a form of exogenous life before we notice any symptoms. By then it could be too late. Perhaps we have mined that stuff and brought tonnes back to Earth and everyone breathed it in and then all